Bbh euectbo-chejcicai



Rama Nov. 16,1926.

This invention relates to a method for the production of alkali metal xanthates, and

considerable quantifies, upon a commercial 5 basis, and the production of an alkali xanthate salt having somewhat dillerent characteristics than the salts heretofore produced principally in containing water of crystallization, as the old product contained no wa- 1 ter'of crystallization.

-Alkali metal xanthates, such as sodium or potassium xanthates-are the salts of xanthic acid, and are produced by bringing .together carbon bisulphide, alcohol, and the 1 hydroxide of the alkali metal.

vention, aims to bring about the reaction 7 between the components'in their nearly theo retical amounts, and to produce the xan- ,20 thate largely in the solid form atonce. This is accomohshed by dissolving the alkali metal Italy xide'in a definite amount of water, an bringing together this solution with the amounts of alcohol and carbon bisul-- phide co ruling to the alkali metal hydroxide use It 15 desirable to keep the amount of water introduced small, in order to decrease the amount of liquid product, and to'accomplishthis, a part of the alkah A, metal hydroxide may be dissolved in alcohol j to form asaturated solution and the remainder dissolved in water. Still another method of out invention consists in letting e water mtroduced combine with the alkali metal hydroxide to form stirring and a metal xanthates are of the form Alkali indicated by the annexed diagram.

UNITED STATES LunwIo aosnns'ram, or rmcrsco, canmonm assronoa onnar was:- nan mezzo-cannon comm, a ooaroaa'nox or cams-om 1 its object is to produce such materials, 1n

finely divided crystals, such as KOHQEO, and bringing together these crystals with Both and xanthate have V -Re.16,414'

PATENT? err-res. V

ETHOID '01 mnucmo ALKLLI-IETLL xan'rna'rns.

No Drawing. original Io. 1,807,988, dated September 2, 1824, Serial Ho. 678,885, fled December 8, 1988.

Application or reissue filed August it, 1826. Serial'lo. 181,804. f

been dproduced by the methods herein disclose r In carrying out the invention with sodium hydroxide, 42 pounds of commercial sodium hydroxide, containing about 94% NaOH is dissolved in 13.5 liters of water. To this solution, while hot, is added denatured ethyl alcohol, 95% by volume of alcohol, and of 28 liters.

. The mixture is then cooled to about 20 centrigrade and to it is added with constant ture of about 20 centigrade, a refined car- 'After the ingredients are mixed and the mass thoroughl cooled, there is discharged about 190 poun of a semi-solid material. The

above described semi-solid material ma be d ried retical guantity given by the chemical equation an containing water of crystallization,

an analysis showing that one form contains two molecules of water of crystallization,

tho it may be that some forms will have the specific gravity of .825 to the amount of stirring and the maintenance of the tempera- 1 bon bi-sulphide to the amount of 28.5 liters. T The method which is the subject of this inmore or less water of crystallization than I shown by this analysis.

If potassium xanthate is to be produced, 52 pounds of commercial potassium hydrox-,

ide containing 88.2% KOH is'dissolved in 12 liters of water. To this solution, while hot, is then added denatured alcohol containi alcohol by volume and having a specific gravity of .825- to the amount of 22 liters and to this mixture cooled to about 720 centigradeis then added refined carbon bisulphid'e to the amount of 24 liters. This solution is then thoroughly mixed. and the. mass cooled, whereupon about 183 pounds of "semi-solid material is discharged, which material when dried gives comme'rcial potassium xanthate, in substantially the theoyield of the chemical equation and retical containing water of crystallization.

In both cases above described, the primary product is largely xanthatesmixed-with materials of uncertain composition produced by .side reactions consisting partly of thio-c'zir bonate-like These materials are in small quantity, and appear to be the nature of thio-carbonates, but their exact composition is difficult of ascertainment.

Alcohol and carbon bisulphide may be mixed first, and the aqueous solution of alkali hydroxide then added.

The above pro ortion's may be varied, the essential points eing that the alkali metal hydroxide is used in connection with water and the chemicals entering into the'reaction in nearly theoretical uantity, the solid produced' wing the xant late in nearly the theoretical quantity on removal of water.

The crystals of sodium xanthate,. thus made will upon bein heated, melt in their own water of crysta lization, and may be converted into the anhydrous salt by drying in vacuum or otherwise.

This method is entirely diiferent from the method of producing this substance described in the literature on the subject which states that water should not be present, and it costs about one half as much to produce in this way as under other known methods. What I claim is as. follows, but modifications may be made in' carrying out the invention and in the above particularly described form thereof, within the purview of the invention as defined by the annexed claims. 1. A method of producing alkali metal xanthates' which consists in dissolving an alkali metal hydroxide in water, adding eth 1 alcohol thereto, cooling the mixture an then adding carbon bisulphide.

'2. A method of producing alkali metal .xanthates which consists in dissolvin an alkali metal hydroxide in water, aft ling alcohol thereto, cooling the mass to about twenty de rees centigrade and adding carbon bisulp ide.

3. A method of producing alkali metal xanthates which consists in. dissolving an alkali metal hydroxide in water, adding to the solution, while hot, ethyl alcohol, coolin the mixture to about twent degrees centigrade, adding carbon bisulp ideto the-mix- .alcohol radical, and water ture and then drying the resultant precipitate. 1

4. A method of producing alkali metal xanthates which consists in adding an alkali metal hydroxide to water, adding ethyl alcohol to the Solution while hot, cooling the mixture to about twenty degrees centigrade, adding carbon bisulphide to the mixture while stirring and cooling, collecting the resultant precipitate and thereafter drying the precipitate. i

5. A method of producing alkali metal xanthates which consists in bringing together an alkali metal hydroxide, water, alcohol and carbon bisulphide.

6-. A method of xanthates which consists in brin ing an alkali metal hydroxide, water, afcohol, and carbon bisulphide together and then drying the solid produced. I l

7. A method ofproducing alkali metal Xanthate which. consists in forming fine crystals of alkali metal hydroxide containing water of crystallization and bringing to gether these crystals with alcohol and carbon bisulphide in the required theoreticalamounts.

8. A method .of producing alkali metal xanthate which consists in adding alkali metal hydroxide to 'water, adding eth 1 alcohol to the solution, adding carbon isulphide in the presence the alkali metal xanthate is not soluble and collecting the resultant precipitate and drying same.

9. A crystalline sodium ing water of crystallization. 10. A crystalline sodium xanthate containing two molecules of water of crystallization.

11. A crystalline sodium xanthate compound containing sodium sulfur, carbon, an of crystallization. In testimonywhereofl have hereunto set my hand this 20th day of August, 1926. LUDWIG {ROSEN STEIN.

producing alkali metal of a liquid in which 7 xanthate contain- 

